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<title>VeraCrypt - Free Open source disk encryption with strong security for the Paranoid</title>
<meta name="description" content="VeraCrypt is free open-source disk encryption software for Windows, Mac OS X and Linux. In case an attacker forces you to reveal the password, VeraCrypt provides plausible deniability. In contrast to file encryption, data encryption performed by VeraCrypt is real-time (on-the-fly), automatic, transparent, needs very little memory, and does not involve temporary unencrypted files."/>
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<a href="Documentation.html">Documentation</a>
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<a href="Key%20Derivation%20Algorithms.html">Key Derivation Algorithms</a>
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<a href="pbkdf2.html">PBKDF2</a>
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<h1>PBKDF2</h1>

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PBKDF2 (Password-Based Key Derivation Function 2) is a widely used KDF that applies a pseudorandom function (HMAC) repeatedly to slow down password guessing. In VeraCrypt, PBKDF2 is available with several HMAC hash functions and is used to derive the keys that decrypt a volume header.
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<h3>PBKDF2-HMAC Variants Supported in VeraCrypt</h3>
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<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><strong>PBKDF2-HMAC-<a href="SHA-512.html" style="color:#0080c0; text-decoration:none">SHA-512</a></strong></li>
<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><strong>PBKDF2-HMAC-<a href="SHA-256.html" style="color:#0080c0; text-decoration:none">SHA-256</a></strong></li>
<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><strong>PBKDF2-HMAC-<a href="Whirlpool.html" style="color:#0080c0; text-decoration:none">Whirlpool</a></strong></li>
<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><strong>PBKDF2-HMAC-<a href="BLAKE2s-256.html" style="color:#0080c0; text-decoration:none">BLAKE2s-256</a></strong></li>
<li style="text-align:left; margin:0px 0px 0px 0px; padding:0px"><strong>PBKDF2-HMAC-<a href="Streebog.html" style="color:#0080c0; text-decoration:none">STREEBOG</a></strong></li>
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<h3>Parameters in VeraCrypt</h3>

<h4>Salt</h4>
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A 512-bit random salt (stored in the volume header) is mixed into the password to prevent precomputation and rainbow-table attacks.
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<h4>Iteration Count</h4>
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The number of PBKDF2 iterations depends on the selected HMAC hash, the context (e.g., system vs. non-system encryption), and the <a href="Personal%20Iterations%20Multiplier%20%28PIM%29.html" style="color:#0080c0; text-decoration:none">PIM</a> value. Increasing PIM increases the iteration count and thus the time required to derive keys. For exact values and formulas, see <a href="Header%20Key%20Derivation.html" style="color:#0080c0; text-decoration:none">Header Key Derivation, Salt, and Iteration Count</a>.
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<h4>Output Length</h4>
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The derived key length depends on the selected encryption algorithm(s) (e.g., 256 bits for AES-256, 768 bits for AES-Twofish-Serpent cascades).
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<h3>Advantages and Considerations</h3>
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<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><strong>Broad compatibility:</strong> PBKDF2 is widely supported across platforms and environments.</li>
<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><strong>Low memory requirements:</strong> Suitable for constrained systems.</li>
<li style="text-align:left; margin:0px 0px 0px 0px; padding:0px"><strong>Not memory-hard:</strong> Compared to <a href="Argon2id.html" style="color:#0080c0; text-decoration:none">Argon2id</a>, PBKDF2 offers less resistance to attacks using massively parallel hardware (GPUs/ASICs). Consider raising PIM if you must use PBKDF2.</li>
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<h3>Related Topics</h3>
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<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><a href="Key%20Derivation%20Algorithms.html" style="color:#0080c0; text-decoration:none">Key Derivation Algorithms (overview)</a></li>
<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><a href="Argon2id.html" style="color:#0080c0; text-decoration:none">Argon2id</a></li>
<li style="text-align:left; margin:0px 0px 6px 0px; padding:0px"><a href="Header%20Key%20Derivation.html" style="color:#0080c0; text-decoration:none">Header Key Derivation, Salt, and Iteration Count</a></li>
<li style="text-align:left; margin:0px 0px 0px 0px; padding:0px"><a href="Personal%20Iterations%20Multiplier%20%28PIM%29.html" style="color:#0080c0; text-decoration:none">Personal Iterations Multiplier (PIM)</a></li>
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